Tempo-spatial thermal comfort analysis of urban heat island with coupling of CFD and building energy simulation

Outdoor thermal comfort (OTC) directly impacts on health and wellbeing of inhabitants while it increases cooling energy demand of buildings. In this regards, different computational models and tools are developed to investigate the impact of built environments on pedestrian thermal comfort. However, in most of these models, the coeffects of solar radiation and local wind velocity are not simultaneously investigated where models are either simplified on solar calculations when are focused on wind or vice versa. This paper proposes a novel simulation framework to develop a high-resolution, but computationally efficient procedure, to couple radiative and convective fluxes in outdoor environments using computational fluid dynamics (CFD) and building energy simulation (BES) approaches. The workflow is implemented in Grasshopper platform fed by outputs of ANSYS-Fluent as the CFD tool and EnergyPlus as the BES tool. The performance of the framework is evaluated using a case study, representing a simplified neighbourhood on a typical hot day. In comparison with the traditional models, results highlight on a considerable change in the OTC values using the proposed model. Results show that the alteration is highly related to the temporal aspects and OTC results experience changes from 5% to 40% in compared to the original OTC values.